The Colorado River used to be host to some species of fish uniquely suited to its formerly murky, silt-laden waters. Since the advent of dams, however, these species have largely been rendered endangered or extinct.
Of the eight native species found in the River before 1963, the Colorado Squawfish, Bonytail Chub and Roundtail Chubhave become extinct. TheHumpback Chub and Razorback Suckerare protected endangeredspecies. Onlythe Speckled Dace, Flannelmouth Sucker, and Bluehead Suckerare still doing well. These fish were able to live in an otherwise inhospitable habitat provided by the old Colorado River.
Humpback Chub
Easily identified by its large hump located directly behind its head, the Humpback Chub is one of the Canyon’s endangered species. The can be found primarily in the Little Colorado River, as they prefer deep, fast moving currents. They were placed on the Federal List of Endangered Species in 1967. Many scientists attribute their massive decline in population to the building of dams in the area because it altered the flow rate of the water.
Arizona Game and Fish closely monitor the Humpback Chub and efforts are being made to alter the flow rate so that it is more conducive to the chub’s natural preference.
Razorback Sucker
The Razorback Sucker is one of the largest sucker species in North America as it can grow up to three feet in length. It can also live more than 40 years!
An already rare species, some believe this species of fish, native to Arizona, may have already been extirpated as there have not been any sightings in recent years. Typically located throughout both the upper and lower Colorado River basins, Razorback Suckers are bottom feeders, primarily eating algae and insect larvae at the bottom of the river.
Speckled Dace
Like the Razorback Sucker, the Speckled Dace is a bottom feeder, primarily feeding on small invertebrate and insect larvae. This whimsically named Speckled Dace is one of the smallest fish found in the Grand Canyon and is actually considered a minnow. They are commonly found in the shorelines and tributaries in the Grand Canyon.
Flannelmouth Sucker
Olive-black in color, the Flannelmouth Sucker looks a lot like the Razorback Sucker. They are native ot the Colorado River system and can be found in the Upper Colorado River Basin. While they are known to live to a hearty 20 years, their numbers are dwindling because the flow rate has been altered since the implementation of dams in the Colorado River.
Bluehead Sucker
These fish look similar to a torpedo and sports a reddish band along his white-gray body. They can be found in the Upper Colorado River Basin and extend into the Lower Basin and into Lake Mead. Like their Flannelmouth Sucker counterparts, Blueheads can live up to 20 years and grow to approximately 20 inches in length.
Rainbow Trout
Today, waters have cleared allowing for algae growth and a completely different habitat. New non-indigenous and hearty species such as the Rainbow Trout have been introduced and are encroaching on their native habitat.
In an effort to stimulate sport fishing and interest, Rainbow Trout were first introduced into Bright Angel Creek by the National Park Service in the 1920’s. Completion of the Glen Canyon Dam and subsequent alteration of the Colorado River complemented the trout’s preferred ecosystem and their numbers flourished.
Although the Colorado River has changed too dramatically to support the life it once did, that is not to say it is void of any. You are likely to see abundant fish and plant life on a boat float down the river.
Did You Know? Sport fishing is allowed in the Grand Canyon National Park. A current Arizona state fishing license is required and different creeks and rivers within the Canyon have different requirements.
If you catch a fish with a tag attached to it, please contact the U.S. Geological Survey’s Grand Canyon Monitoring and Research Station at (928) 556-7323. Anglers may keep or release tagged fish, but researchers ask you give them the tag number and location of where the fish was caught for monitoring purposes.